A successive approximation analog-to-digital (A/D) converter is a type of analog-to-digital converter that converts a continuous analog waveform into a discrete digital representation via a binary search through all possible quantization levels before finally converging upon a digital output for each conversion. The integral non-linearity (INL) of a successive-approximation A/D converter is dependent on the INL of a D/A converter circuit (e.g., reference voltage generator) in the successive-approximation A/D converter. Thus, the INL of the successive-approximation A/D converter deteriorates if there is great variability among the elements used within the D/A-converter circuit (e.g., reference voltage generator).